<template>
    <div>
      <!-- 无id时, 可以使用index(反正也是就地更新) -->
      <div
        v-for="(item, index) in arr" style="display: inline-block" :key="index"
      >
        <input type="checkbox" v-model="arr2" :value="item" />
        <span>{{ item }}</span>
      </div>
      <p>你选中的元素, 累加的值和为: {{ theSum }}</p>
    </div>
  </template>
  
  <script>
  export default {
    data() {
      return {
        arr: [9, 15, 19, 25, 29, 31, 48, 57, 62, 79, 87],
        // arr2: [],拿一个空数组接
        arr2:[]
      };
    },
    computed: {
      theSum() {
        return this.arr2.reduce((sum, x) => {
          return (sum += x);
        }, 0);
      },
    },
  };
  </script>
  
  <style>
  </style>